A hydrazine (HYD) detection method is presented based on molecularly imprinting polymers (MIPs) and cobalt-barium stannate nanoparticles incorporated-functionalized MWCNTs (CBSNPs/f-MWCNTs) nanocomposite. Firstly, co-precipitation and sonication techniques were applied to the preparations of CBSNPs and CBSNPs/f-MWCNTs nanocomposite, respectively. Since waste generation occurs at a minimum level in these techniques, an environmentally friendly nanocomposite was prepared. After the glassy carbon electrode modification with CBSNPs and CBSNPs/f-MWCNTs nanocomposite, HYD imprinted electrodes were fabricated using cyclic voltammetry (CV) with a dispersion containing 100.0 mM pyrrole (Py) monomer and 25.0 mM HYD molecule. The resulting electrochemical sensor demonstrated a detection span of 1.0 × 10−9 M to 1.0 × 10−8 M HYD and achieved a detection limit (LOD) of 3.0 × 10−10 M. Furthermore, the developed electrochemical sensor was used for actual tap water samples, and the obtained values close to 100.00% in recovery experiments showed the high accuracy of the developed sensor in real sample analysis. Finally, the selectivity, stability, and reproducibility of the created electrochemical sensor were investigated, and the developed sensor has been demonstrated to have high stability for at least 7 weeks, high reproducibility with a relative standard deviation (RSD) value of 0.14%, and high selectivity in real samples.